Signal transmitting apparatus with coding wheels



June 27, 1950 BE|Q 2,512,734

SIGNAL TRANSMITTING APPARATUS WITH CODING WHEELS Filed May 28, 1948 2 Sheets-Sheet 1 "unuullllnlw Lu; Attorney June 27, 1950 BECCIIQ 2,512,734

SIGNAL TRANSMITTING APPARATUS WITH CODING WHEELS Filed M a y 28, 1948 2 Sheets-Sheet 2 INVENTOR GIUSEPPE BECCIO Patented June 27, 1950 SIGNAL TRANSMITTHWG APPARATUS WITH CODING WHEELS Giuseppe Beccio, Milan, Italy Application May 28, 1948, Serial No. 29,813 In Italy May 30, 1947 3 Claims. 1

The present invention relates to signal transmitting apparatus having a coding device of a known type, briefly outlined hereinafter, and designed to code the signals transmitted at the transmitting station and to decode them at the receiving station.

The said coding device includes a set of wheels or code discs having pins on one side of each code disc, said code discs being associated with the levers acting on the signal transmitting means in such a way that the polarity of the impulse which is transmitted will or will not be inverted, according to the position of the pins in respect to the said levers and according to the prevailing position of the transmitting means. The inversion of the polarity thus obtained determines the coding.

The object of the present invention is to provide a device for advancing the code discs in a signal transmitting machine, in which the coding is performed in the manner set forth above.

In the said device the means which effect the advancement of each code disc carry a disengagement member or disabling member which is subject to be operated by the pins of the following wheel so as to determine the disengagement of the said means from the associated code disc.

Thus the movementof each code disc depends on the presence or absence of a pin of the following code disc along a fixed generatrix.

Other objects and structural details of the invention will be apparent from the following description when read in connection with the accompanying drawings, wherein:

Fig. 1 is an illustration of the invention as embodied in a coding and decoding device applied to a start-stop printing telegraph apparatus operating on the so-called five unit alphabet, wherein the signals transmitted and received are represented by a series of five impulses,

Fig. 2 is a fragmentary perspective View illustrating two adjacent code discs and advancing members associated with said :code discs, and

Fig. 3 is a fragmentary perspective view similar to that shown in Fig. 2, wherein, however, the elements are in a different position.

For simplicitys sake the drawings illustrate only means related to a single impulse. Therefore, Fig. 1 illustrates the sender, the coding device, the decoding device and the receiver related to a single impulse.

Before describing the mechanism for advancing the coding wheels, there will be disclosed the coding and decoding device applied to said startstop printing telegraph.

I is a transmitting combination bar which by the depression of a key lever 2 is longitudinally movable into its right hand or left hand end position.

On the bar I there is pivoted at 3 a bell-crank lever 4, the upper arm of which cooperates by means of a pin and slot connection 5 with a lever Ii swingably mounted at 'l.

The lever B is urged in a, clockwise direction by a spring I9 whereby in the position shown in Fig. 1 the end portion 8 of the lever 6 is held in contact with one of the controlling pins-9 projecting from one side of a wheel or code disc I0 loosely mounted upon a shaft II and prevented from moving by a latch I2. Each code disc I0 is divided into an equal number of parts, for example twenty-six; each division corresponds to a tooth and is marked with a letter'of the alphabet which can be read through a window in the cover 51.

The lower arm of the bell-crank lever 4 is movable into the path of the projection II of a lever I3 pivoted at I4 and urged in a clockwise direction by its spring I5. The lever I3 cooperates with the cam I6 mounted upon the transmission shaft well known in any start-stop printing telegraph apparatus. The lower arm of the lever I3 controls the transmission contact I8.

If the combination bar I is moved by a keylever 2 into its right hand end position, the lever 4 is rocked in a counter-clockwise direction so that its lower arm lies in the path of the projection II. During a cycle of the cam It the lever I3 will be prevented from rotating and the contact I8 will not be closed.

Thus, if the end 8 of the lever B is in contact with a controlling pin 9 there will be the following relation: if the bar I is in its left hand end position there will be an electrical impulse; if the bar I is in its right hand end position there will be an interval.

If the code disc I0 is rotated in such a, way that there will be no pin 9 in front of the end 8 of the lever Ii, this lever will be permitted to rotate in a clockwise direction until its right hand end will contact the pin 20 secured to the machine frame, whereby the lever 4 will rock in a counter-clockwise direction. If the bar I is in its left hand end position the lower arm of the lever 4 will lie in the path of the projection I! so that during a cycle of the cam I6 the lever I3 is prevented from rotating and the contact I8 will not be closed.

If the bar I is moved into its right hand end position the lever 4 is further rocked in a counoer-clockwise direction so that its lower arm will be out of the path of the projection H on the right hand side of the latter. During a cycle of the cam I6 the lever I3 is permitted to rotate and to close the contact I8.

Thus, if the end 8 of the lever 6 does not contact a pin 9 so that the lever 6 contacts the pin 20, there will be the following relation: if the bar I is in its left hand end posit-ionthere will be an interval; if the bar I is in its right hand end position there will bean impulse.

Therefore, it is obvious that the presence or absence of a pin 9 in front of the end 8 of the lever B eifects the inversion of the relation between the position of the combination bar'I and the sign of the outgoing impulse.

Assume now the code disc It) does not move, so that the combination of pins 9 in front of the ends 8 of the series of levers 6 remains constant, both at the transmitting station and at the'receiving station.

The impulses transmitted by'the contact I8 arrive at the electromagnet'2l of the receiving mechanism. The first impulse is a start-impulse which will never be coded; in the case of the present machine it is an interval. The electromagnet 2| is de-energized and the armature 22 pivoted at 23 and urged in a clockwise-direction by its spring 24 rocks clockwise till it-contacts the'pin 25 secured to the machine frame. This movement of the armature-causes in-a manner known per se the starting of the receiving shaft, well known 'in-the start-stop printing telegraphs, with the cams mounted thereupon; one of these cams is the cam 26.

In a bent-over portion of the armature22 there is an opening 21 cooperating with a projection 28 of 'a lever-29 pivotedat '36 on the lever 3|; this last mentioned lever pivoted at 36 is urged by a spring 31 in a clockwise direction. According to the positions of the lever 29 and of the armature '22 the projection 28 will be permitted to pass through the opening '21 or it will be stopped by the lower or upper portion of the bent-over frame. a lever 33 by means of the'pin and slot connection 32. The lever 33 pivoted at is urged in a counter-clockwise direction by its spring '45. In the position shown in Fig. 1 the end 35 of'the lever '-33'is held in wcontact with-the same pin 9 which cooperates with-the end 8 of the-lever '6.

The lower arm 42 of the lever 3i cooperates with a lever 38 pivoted at 39 and urged in a clockwise direction by its-spring. The lower arm of the lever 38 acts upon the selectingbar 43 by means of a spring "44 tensioned between said arm and said selecting bar. The cam 23 mounted on the receiving shaft is able'to swing the lever 38 in a counter-clockwise direction during a cycle of said shaft.

After the transmission of the start-impulse, which causes the armatuIe ZZ to=-be rocked clock- Wiseby its spring 24 as outlined l'iereinbefore, the five impulses representing the signal arrive at the electromagnet 2|. It is now assumed that the first impulse following said start-impulse is transmitted when the-end 8 of the lever 6 contacts a pin -9 of the code disc II! and when the bar I is in its left hand end position. Therefore, the first impulse will be a positive one which energizes the electromagnetZl so that the armature 22 is swung upwardsdnto the'position shown in Fig. l.

As the end :35 of the .lever.33 contacts a pin 9,'the opening 2! lies in the path of theprojec- The'lever 29 cooper-ates with tion 28 of the lever 29. During a cycle of the cam 26 which rocks the lever 38 counter-clockwise the projection 28 passes through the opening 27; this, however, does not interfere with further movements of the armature 22 owing to the form of the projection 28. The lever 3I is permitted to rotate till its lower end 42 contacts the uppermost projection of the lever 38. Thus, the lever 38 is engaged in its rocked position, with its tooth 4| locked by the lower end 42 of the lever 3|, and the selecting bar 43 is urged to its right hand end position by the spring 44.

Therefore, it is obvious that, if the ends of the levers 6 and 33 contact a pin 9, a selecting bar 43 is -in its right hand end position when a transmitting combination bar I is in its left hand end 1 position.

If the transmitting combination bar I is in its right hand end position, the electromagnet will be deenergized, the armature 22 will rock in a clockwise direction so that during a cycle of the cam 26 the projection 28 will be prevented from moving by the upper portion of the bent-over frame being in its path. The lever 38 will not be engaged in its rocked position and the selecting bar 43 will be restored into its left hand end position.

In this case a selecting bar 43 is in its left hand end position when a transmitting combination bar I is in its right hand end position.

It is now assumed that there is no pin 9 in front of the ends of the levers 6 and 33 so that said levers are rocked each by its spring till they contact the pins 20 and 46 respectively. If the transmitting bar I is in its right hand end position the electromagnet 2| is energized and the armature 22 is rocked counter-clockwise.

During a cycle of the cam 26 the projection 28 will be prevented from moving by the lower portion of the bent-over frame, because the lever 29 has been rocked clockwise by the lever 33.

The lever 38 will not be engaged in its rocked position and the selecting bar 43 will be restored into its left hand end position. In spite of the inversion of the sign of the impulse produced by the lack of a pin 9 infront of the ends of the levers fi-and 33, a selecting bar 43 is positioned in its left hand end position when a transmitting bar I is in its right hand end position.

If the transmitting bar I is in its left hand end position, the electromagnet 2| will be deenergized and the armature 22 will rock clockwise. The opening 21 will lie in the path of the projection 28 which will be permitted to pass. The lever 38 will be engaged in its rocked-position and the selecting bar 43 will be moved to its right hand end position by thev spring 44. In this case, a selecting bar 43 is in its right hand end position when a transmitting combination bar I is in its left hand end position.

It is therefore obvious that in all cases a selecting bar is in its right hand end position when a transmitting combination bar is in its left hand end position, and vice versa. In the receiving mechanism at the transmitting station and at the receiving station the signals are thus registered decoded, While they run coded all over the line. Naturally, it is necessary that the combination of pins 9 in front of the end of the levers-6 and 33 be identical in both the transmitting and receiving stations during the transmission and the reception of a signal. For obtaining the coding of the outgoing signals the said combinations have to be varied at each signal; it is sufficient that the pins 9 do not move from thebeginn'ing of the is determined horizontally by the position of the pivot 30 carried by the lever 3| and is determined vertically by the position of the pin 32 inside the slot of the 1ever33. The lever 3| is stopped by the engagement of its lower end 42 with the uppermost step of the lever 38, while the pin 32 slides in the slot of the lever 33 which remains in its position. At the beginning of the next cycle a cam (not shown) mounted on the receiving shaft carrying the cams 26 and 41 acts on a projection (not shown) arranged at the right hand side of the lever 3| above the plane of the shaft 35, whereby the lever 3| is returned into its starting position shown in Fig. 1 and the spring 3! is tensioned. The return of the lever 3| into its starting position causes the resettin of the projection 28. The tensioning of the spring 31 causes all levers 3! arranged. on the shaft 36 and rocked in clockwise direction during the preceding cycle to return in counter-clockwise direction into the position shown in Fig. 1

Having now described the coding and decoding device applied to a start-stop printing telegraph, there will be disclosed hereinafter the mechanism according to the invention for advancing the code discs of said coding and decoding device.

At the end of each signal, a special device which in the case of the start-stop printing telegraph is the cam 41 mounted upon the shaft carrying the receiving cams pushes upwards the lever 48 pivoted at 49 and urged in a counterclockwise direction by the spring 50.

On the lever 48 along the axis there are pivoted a number of advancing members or levers 54, 54a equal to the number of code discs I0. When a lever 54 by means of its tooth 53 engages a tooth of the associated code disc in (see Fig. 2), this code disc will be advanced one step. The code disc II) is then held'in the new position by the latch I2 (Fig. 1). Beyond the tooth 53 which cooperates with the corresponding wheel III, the lever 54 has a projection forming a disabling member or lug 55 which lays in the path of the controlling pins 9a of the following or adjacent code disc Illa.

Upon an advancing of the following or adjacent code disc Ina by its associated lever 54 a controlling pin 9a of said adjacent code disc [0a can thus act on this disabling member or lug 55 pushing the lever 54 counter-clockwise so that the tooth 53 cannot come into engagement with a tooth of the associated code disc in (see Fig. 3). Thus, when the lever 48 is swung upwards by the cam 41, the lever 54 does not rotate the code disc l0. However, if there is no pin 90. of the following or adjacent code disc Illa. in front of the disabling member or lug 55, the tooth 53 is permitted to engage a tooth of the code disc In (Fig. 2) and to advance same one step when the lever 48 is swung upwards.

The last code disc of the set of code discs l0, Illa will always rotate one step during each cycle of the cam 41 because no code disc follows, so that there are no pins which can act on the disabling member or lug arranged on the last advancing member or lever. Thus the advance- 7 ment of all code discslfl, lfl'a except the'last one is affected by the pins of the following wheel, so that the rule by which each code disc acts on the levers 6 and 33 does not only depend on the position of the pins 9 that it carries, but also on the position of the pins 9 of all the following code discs. As the last code disc of the set advances one tooth during each cycle of the cam 41 it is advisable, in order to make more complex the rule,

of coding, to interpose other wheelsor discs between the one which' advances one step at each signal and the five which act on the illustrated devices. g

Naturally at the beginning of the transmission, the set of code discs on the two machines which are connected, should be in the same position. This can be determined by reading through the window in the cover 51 of the two machines, the same group of letters of the alphabet. This group of letters constitutes the key.

As stated in the beginning, the device has been described as applied to printing telegraphs in order to make it easier to be understood; nevertheless it can also be applied to any coding mechanism in which each signal is formed by a certain number of elements and where it is not necessary that the machines be connected electrically. As for example: a coding machine can prepare a perforated tape by means of a perfo-' rating mechanism fitted in place of the transmission switch so that the holes will correspond to the coded signal. In the decoding machine the tape will be sensed by appropriate sensing means, fitted in the place of the receiving mechanism and adapted to act upon the printing mechanism of the machine.

While it has been described herein what is considered a highly desirable embodiment of the present invention, it is obvious that many changes in form could be made without departing from the spirit of the invention, the basical characteristic of which is to provide a device for advancing the coding wheels in such a way that the advancement of each coding wheel depends on the position of the pins 9 borne by the following wheel, whereb the number and position of said pins can be varied at will as well as the number of wheels can also be changed.

What I claim is:

1. In a ciphering and deciphering machine the combination of: a keying device including a set of code discs, a shaft, each code disc of said set of code discs being rotatably mounted on said shaft, a mechanism for translating a primary text into a secondary text, means associated with said code discs for governing said translating mechanism, a drive for rotating said code discs, said drive including a set of advancing means, the number of advancing means being equal to the number of code discs, each advancing means being settable into an active position wherein it is in operative engagement with its associated code disc for advancing same and into an inactive position wherein it is out of engagement with its associated code disc, and controlling means arranged on the rotatable code discs for controlling the active and inactive positions of the advancing means, the advancing means associated with a predetermined code disc being arranged for cooperation with the controlling means of the rotatable code disc adjacent to said predetermined code disc whereby the active and inactive positions of the advancing means are controlled by the positions of the 

